Astronomers discover potentially habitable planet 12 light-years away

Artist's impression of the Tau Ceti system. Image via J. Pinfield for the RoPACS network at the University of Hertfordshire (2012)

A group of astronomers may have detected a planet that could support human life and which is hosted by the Earth’s nearest single sun-like star Tau Ceti, at just 12 light-years away.

The team of international astronomers, led by scientists at the University of Hertfordshire, may have found that Tau Ceti, one of the 20 closest stars to Earth, hosts five planets, including one in the star’s ‘habitable zone’ – meaning that the planet, if it exists, could potentially support human life.

The scientists have published an online paper that will appear in Astronomy and Astrophysics.

Tau Ceti is just 12 light-years from Earth and the star can be glimpsed with the naked eye in the nighttime sky.

The scientists involved in the study estimate that the five planets hosted by Tau Ceti have masses between two and six times the mass of Earth. They say that this would make it the lowest-mass planetary system ever detected.

The planet that could lie in the habitable zone of Tau Ceti has a mass around five times that of Earth.

The astronomers, who hail from the UK, Chile, the US and Australia, combined more than 6,000 observations to model the data, which suggests that Tau Ceti is not a lone star.

"We pioneered new data modelling techniques by adding artificial signals to the data and testing our recovery of the signals with a variety of different approaches. This significantly improved our noise modelling techniques and increased our ability to find low-mass planets," said Mikko Tuomi from the University of Hertfordshire.

James Jenkins from the Universidad de Chile said that because Tau Ceti is so bright and one of planet Earth’s nearest cosmic neighbours, scientists may be able to study the atmospheres of these planets in the not-too-distant future.

"Planetary systems found around nearby stars close to our sun indicate that these systems are common in our Milky Way galaxy," he said.